Improvement in the manufacture of railroad-rails



UNITED STATES PATENT OFFICE.

ZADOK STREET, OF SALEM, OHIO.

IMPROVEMENT IN THE MANUFACTURE OF RAILROAD-RAILS.

Specification forming part of Letters Patent No. 53,701, dated April 3,1866.

To all whom it may concern:

Be it known that I, ZADOK STREET, of Salem, in the county of Oolumbianaand State of.

Ohio, have made new and useful Improvements in Case-Hardening IronRailroad-Rails; and I do hereby declare the following to be a full,clear, and exact description of the nature of the same, snfficient toenable one skilled in the art to which it is allied to use the same.

The invention consists in case-hardening railroad-rails. It is speedy inits action, and applicable to many purposes when the iron cannot beheated in connection with charcoalas in muffler, for instanceand at thesame time it does the work more effectually than can be accomplished bythe application of prussiate of potash alone.

The compound used consists of vegetablecharcoal, one part;animal-charcoal, one part; prussiate of potash, one part. Animal oil ortallow may be substituted for the charcoal.

I am aware that all these ingredients have been used in processes forcase-hardenin g iron, but not combined together or applied as I propose,which is as follows: The bar or piece of iron being heated to acherry-red, the compound is placed upon it, and the iron quickly absorbsthe carbon therefrom, making the chemical change required for theconversion of iron intosteel. The common plan of using prussiate ofpotash makes a hard and very brittle but thin scale of steel on thesurface of the iron, which is not satisfactory on several accounts. Itis neither deep nor tough enough, and will not bear'blows.

The process of case-hardenin g with charcoal is tedious and requirescertain facilities for its ready application but by my process theheated iron, by a simple and direct application, is ease-hardened withalmost or quite the facility that it is accomplished by prussiatc ofpotash, and in a much better manner as respects the toughness of thesteel and its depth.

The special application of the compound consists in hardening the end ofrailroad-rails, whereby they are rendered equal in endurance to theother portions of the rails. It is well known that, owing to their wantof support and the incidents of slight differences in elevation, theends of rails become battered and injured long before the balance of therail is unfit for service. When desired the whole upper surface of therail may be so treated.

Having described my invention, what I claim therein as new, and desireto secure by Letters Patent, is

The combination of animal-charcoal, vege table'charcoal, or othercarbonaceous material, such as animal oil or tallow, and prussiate ofpotash, in about the proportions specified, and for the purpose ofhardening railroad-rails, as set forth.

To the above specification of my improvement in case-hardening I havesigned my hand this 9th day of February, 1866.

ZADOK STREET.

Witnesses EDWARD H. KNIGHT, W. F. HALL.

